Vents, for venting gases, such as air, through the roof of a building are well known. Such vents are used in a wide variety of applications, including in the venting of air from a bathroom or from a stove in a kitchen. In such circumstances, the vent is interconnected by way of flexible or rigid piping or ducting to an exhaust fan, which draws the air from the location and forces it through the piping and out of the vent at the roof.
The air vent itself is generally comprised of several parts including a conduit which includes an inlet for a connection to the piping, and a cover. The cover, as its name indicates, covers the outlet of the conduit, assisting to prevent rain or snow from entering the conduit, which could then pass down the piping. Air vents also typically have a hinged door flap mounted within the cover, which pivot between a closed position, wherein the cover substantially covers the outlet, and an open position wherein the forced air exiting the conduit's outlet can pass out of the vent through the opening in the cover. Louvres or vanes mounted within the opening of the cover also serve to help inhibit water and snow from entering the pipeline by way of the roof vent.
Although the door flap and the louvres serve the purpose of inhibiting the movement of moisture into the pipeline, there are particular extreme weather conditions where a further barrier to the moisture is highly desirable. As the door flap merely rests against the base of the vent, and typically is only a plastic surface meeting and contacting a plastic surface under the weight of the door flap, there is no positive seal between the base and the flap. The same is true at the side and rear edges of the flap, in so far as there is no positive seal with the walls of the cover. Thus in conditions of hard, wind driven rain, it is not unusual for moisture to be driven through the cover opening and past the door flap, and may thus reach inside the pipeline.
It is highly undesirable to have moisture seep into the pipeline. Aside from the matter of an increased chance of corrosion of the pipeline, if it is made from a material that is susceptible to corrosion, there is also the risk that water might reach the exhaust fan or another electrical appliance and cause damage thereto. Accordingly, it is desirable to have a further means to inhibit the movement of water from outside the vent into the pipeline. However, it is important that any additional features not add significantly to the overall cost of manufacturing the roof vent.
The roof vents also have a way to permit the vent to be secured to the roof. Typically, the vent is placed in a hole in the roof and secured in position by connecting a base to the frame of the roof, placing flashing over the base and then the roof material, such as roof shingles, is put in place over the flashing. It is usually only after the roof has been put in place, that the connection of the pipeline to the inlet of the conduit can be, and is, made. This however is a somewhat difficult and awkward task for the installer, as he/she has to make a connection between two sections of pipe, usually requiring clamping etc. in a confined, raised space (eg. in the attic of the building). It is thus desirable to have an improved way of connecting a roof vent to a pipeline.